In my last post, I started reviewing the anticoagulant reversal section of the Austrian consensus statement on TBI patients taking anticoagulants. Due to its length, I covered only anti-platelet agents. Today I’ll discuss their findings on reversing Vitamin K antagonists.
Q1. Should Vitamin K antagonists (VKAs) be reversed in case of hemorrhagic TBI?
Answer: That’s simple. Yes!
Q2. Should Vitamin K be administered to reverse the effects of VKAs?
Answer: Yes, as an adjunct to other reversal agents. The usual dose is 5-10mg IV.
Adjuncts must always be used, because Vitamin K only enables the liver to produce factors II, VII, IX, and X. This is not an immediate process, and may take up to 24 hours for the INR to fall to reasonable levels. Additional treatment is needed to raise these factor levels quickly.
Q3. Should prothrombin complex concentrate (PCC) and/or plasma be used for reversal of VKAs?
Answer: Four-factor PCC is the treatment of choice, and is preferred over plasma.
Reversal of VKAs with plasma requires administration of large volumes, and each unit is given over one to two hours. This results in a slower correction when compared to PCC, which occurs in less than 30 minutes. And many elderly patients with comorbidities cannot tolerate the colloid volume administered with multiple units of plasma. Multiple studies have shown that patients treated with PCC achieve their target INR significantly faster and have less hematoma progression than those treated with plasma.
Q4. Should recombinant activated factor VII (rFVIIa) be used for reversal of VKAs?
This drug was the darling in trauma care around the turn of the century, but has since fallen into disuse. The few studies available show that there may be INR rebound and more frequent hematoma expansion compared to PCC.
Next post: Recommendations for reversal of DOACs.
Reference: Diagnostic and therapeutic approach in adult patients with traumatic brain injury receiving oral anticoagulant therapy: an Austrian interdisciplinary consensus statement. Crit Care 23:62, 2019.